Nelly, I tried the fiber thing and it actually made things worse--just more D quantity wise with a stringy texture & funny colour.
The probiotics actually caused me more problems--pain & trapped D, if that makes sense. It's kind of like the cement casing metaphor you used. actually. I've stopped with the enzymes due to the narrow stools. Beano, however, works just fine for me. Ditto for simethecone.
I am highly D prone if I wear tight waisted clothing. If I chew gum I pay the price. I had to stop smoking because it make my D worse from the air swallowing/sucking. I also have a list of "acid fiber bombs" as you call them.